But, if constructing the future and settling everything for all times are not our affair, it is all the more clear what we have to accomplish at present: I am referring to ruthless criticism of all that exists, ruthless both in the sense of not being afraid of the result it arrives at and in the sense of being just as little afraid of conflict with the powers that be.

The philosophers have only interpreted the world, in various ways; the point, however, is to change it.

The work of Marx has had a profound effect on 20th century politics and art. Many of the artists associated with Surrealism left the movement for Communism, including Eluard, Aragon and Ernst. Poststructualism has needed to confront Marxism, and you can find the effect of that confrontation in the work of Lyotard, Foucault, Derrida and others. Samuel R. Delany has also identified himself as a Marxist, and you can see how that infiltrates his sf and non-fiction.